Change-speed mechanism and control



March 12, 1940. A. THOMPSON 2,193,304

CHANGE-SPEED MECHANISM AND CONTROL Filed Oct. 16, 1935 9 Sheets-Sheet 1 March 1 2, 1940,

Filed Oct. 16, 1935 9 Sheets-Sheet 2 March 12, 1940. E, A, THOMPSON 2,193,304

CHANGE-SPEED MECHANISM AND CONTROL Filed Oct. 16, 1935 9 Sheets-Sheet 4 12, 1940. o soN 2,193,304

CHANGE-SPEED MECHANISM AND CONTROL Filed Oct. 16, 1935 9 Sheets-Sheet 5 Ill.

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March 12, 1940. E. A. THOMPSON 72,193,304

CHANGE-SPEED MECHANISM AND CONTROL Filed Oct. 16, 1935 9 Sheets-Sheet 6 March 12, 1940. E. A. THOMPSON CHANGE-SPEED MECHANISM AND CONTROL 9 Sheets-Sheet 7 Filed Oct. 16, 1935 3 u w c n for, 0111 0502:

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CHANGE-SPEED MECHANISM AND CONTROL Filed 0612. 16, 1935 9 Sheets-Sheet 8 & PART nmorru: upsmn sovsmaon ENFORCE, u 6 I oowusmrr z T g g A IO 20 50 40 5o 60 7o MILES PER noun (4021 4415 March 12, 1940. E. A. THOMPSON 7 SPEED MECHANISM AND CbNTROL Filed Oct. 16, 1935 CHANGE- 9 Sheets-Sheet 9 mm NQ amen m Patented Mar. 12, 1940 CHAN GE-SPEED MECHANISM AND CONTROL Earl A. Thompson, Birmingham, Mich, assignor" to General Motors Corporation, Detroit, Micln, a corporation of Delaware Application mm 1c, 1935, Serial No. 45,184

59 Claims.

The development of invention in this my present application is related to my prior U. S. Serial Number 659,752 filed March 8, 1933 and to my U. S. Serial Number 747,386 filed October 8, 1994.

In the first of these I show the utility of my automatically controlled unit in conjunction with a gearshift of standard character, my unit providing automatic changes for a range of hand selected speed ratios.

In the second application, I show improvements in smoothness of transition from one ratio to another, and a degree of mastery vested in the operator-operable control members at any time. such that a high degree of safety in practical use is obtained.

The controls for transmission units connected in series between the power and the load for obtaining the full use of the transmission ratio ranges must establish a regime wherein during a shift from lowest ratio to highest ratio or vice versa, it is necessary to execute a simultaneous or nearly simultaneous shift in multiple units.

An example of this is in seriatim two-speed gearing designed to provide four forward speeds. In

such an assembly, first will be low gear in both units; second will be by low in one unit with the other in direct drive; third will be by direct drive in the first unit, with low in the second.

High will be direct drive in both units.

30 During a transition from second" to third a change in both units is required. The alternatives are to interrupt the torque path in one unit, make the shift in the second unit during the nodrive period of the first, and then complete shift in the first unit; or else make the effort to establish a simultaneous shift in both. The first alternative often results in a lurching of the drive, and the high inertias of the rotating parts are difllcult to absorb Without unpleasant notice to 40 passengers and driver. The complications of sequence controls so as to avoid jerks and uneven and lengthy shift intervals are also troublesome from the point of view of mechanical adjustment and retention of desired sequences of ratios. In

the present arrangement of my invention simultaneous or practically simultaneous shift operation in both units is achieved, for superior advantage in a smooth change speed interval, quickly established and completed. Proper'in- 50 ertia absorption means are essential to that speed change interval which is preferred for quietness and lack of shock in transfer to a new driving condition.

In the general art of automatically operable or 55 self-changing gearing, there are wo ordinary types; first, wherein theno-drive interval of shift is established by opening of a main clutch; and second, wherein the main clutch need not be manipulated, the elements within the transmission providing all of the essentials for the no- 5 drive interval. My invention discloses the latter, with improvements in simplicity over the first noted, and a resulting economy in the number of parts.

My combination of epicyclic gearing provides 10 advantages in quietness and smoothness of ratio shift operation characterized by means to drive through helical gearing wherein axial thrusts and displacement forces are absorbed, or selfcancelling, and prevented from disturbing the 15 alignment and adjustment of other units with which the epicyclic units are associated.

Another specific feature of my improvement lies in the creation of a type of gear unit which has particular utility in auxiliary ratio drive, due 20 in part to its inherent ability to handle thrusts in a self-contained manner in small space, which provides special applicability to reaction mount- 1 My improvement also includes a compound reduction drive wherein a greater range of ratio differences are available than in the common or simple types of planetary transmissions. My disclosure is of a true planetary gearing in which planetating action is had under torque as distinct from gearing in which rotatable counter gear carriers may be braked for speed ratios other than direct drive. The combination of scalar ratios herewith provided is likewise of unusual utility..

In the preferred construction, the invention is shown embodying in one form a change speed gear unit which may be utilized by itself as a ratio changer between a prime mover, clutch and a load to be driven; or which may be included in an assembly of change speed devices operating between a power and a load shaft, as described herewith. This showing is in the form of epicyclic gearings having 1 alternate torque paths, one for example being a direct drive, another through gearing of double compounded form. In this embodiment; friction elements are used to connect direct drive and to set up drive through gearing, certain of said elements being normally biased to act in establishing one of the paths, and disconnectable by auxiliary power under the control of the operator.

An important feature of my invention is the manner of control by which automatic operation is had, yet in which overriding master control means may set aside the automatic selection and compel drive in a desired driving ratio.

My disclosures herewith show special advantages in the general assembly arrangement from the standpoint of low cost, rigid support of es.- sential elements and ease of assembly, exemplified by the use of a partitioned case into which compartments the various gear units may be readily assembled, and completely sealed by a relatively light pan which serves as a lubricant sump. These advantages by reduction in mounting and assembly expense make it possible to extend the use of the disclosed improvements to low cost passenger cars.

The interconnection of the controls of my device with related controls of associated prime movers and variable speed transmission and clutch units is likewise herewith disclosed for a compounded power control regime wherein are obtained correlated functional change-speed effects.

In the present disclosure, while epicyclic gearings of simple and double compounded structure are shown, with a special development of selfsupporting thrust absorption means combined with helical gearings, novelty and utility lie in the special advantages of quietness and the elimination of excessive axial movement between reaction elements and frame, for example; and in the pressure circulation of lubricant through a gear tooth system, in continuously moving paths, with a consequent saving in heat losses and in more uniform lubrication. I also provide a positively acting heat exchanger in this latter combination.

Additional features of novelty in my disclosure as regards auxiliary power supply, alternate actuation of selected speed ratio compelling mechanism, reciprocal and coordinate automatic controls therefor, involving combinations of driver will and driving conditions, and master selection controls capable of superceding automatically selected speed ratio settings will be apparent upon inspection of the following specifications.

Figure 1 shows the appearance of one form of my invention as mounted with the engine and transmission assembly of a motor car which it is designed to control. The view is taken from the left side of the motor car chassis, and represents all of the external appearing items of the particular form described.

Figure 2 is a view of the steering column area from above, showing the hand selection controls.

Figure 2a is a view of the position latch means and the handlever which cooperates with the sector plate of Figure 2.

Figure 3 shows a modification of the handlever control mechanism of Figures 2 and 2a. Figure 4 is a vertical section of the assembly of transmission units, with the engine connections at the right; the load'shaft being to the left. This view'shows the servo and lubrication supply means, the lubricant cooling. means, the lubrication system, and the bearing and thrust "supporting means. Various sections in other figures are taken from Figure 4 as a reference.

Figure 5 is a plan view in section with parts broken away taken about line 5 of Figure 4 of the forward-neutral-reverse unit showing the drive to the governor mechanism.

Figure 6.1a a vertical section taken through line 6-6 of Figure 4, to show the arrangement of gearing of the forward-neutral-reverse unit, and the oil pump and delivery system for lubrication and servo purposes.

Figure 7 is a partial section of the oil cooler shown partly in Figure 6.

Figure 8 is an elevation section taken on line l-l of Figure 4, showing the actuating mechanism for the manual unit, and the control levers mounted on the left side of the transmis sion casing shown in perspective in Figure 1.

Figure 9 gives a detail of the clutch pressure porting shown in section and taken substantially on line 8-9 of Figure 4. Figure 10 is a section at lO-ll of Figure 4 showing clutch pistons, plates and supports. t

Figure 11 is a side elevation of the control assembly and valve mechanism of Figure 8.

Figure 12 describes in perspective the valve casing and valves which control the automatic and manual units, with porting connected to lines leading to the cylinders of Figures 8 and 9. Figure 13 shows a detail of the cross connecting porting of Figure 11.

Figure 14 is an enlarged view of the assembly of externally mounted ratio control levers mounted on the left side of the transmission casing as in Figure 1.

Figure 15 is similar to Figure 11, and shows the corresponding internal control lever assembly in proper relationship to the external view of Figure 14.

Figure 16 is a detail of construction of a control part for the mechanism of Figures 11 and 15.

Figure 17 is a plan section taken on line llll of Fig. 14 showing the ratio shift control connections between the external lever linkages of Figures 14 and 15. Figure 18 shows a view within the compartment of Figure 15, of the lever joining the governor-accelerator linkage to the control valve for the automatic unit. 7

Figures 19, 20, 21 and 22 show the various operating positions of the fluid pressure tomatic valve control of Figure 6.

Figures 23, 24, 25 and 26 show the different positions of the control valve of the manual unit, in setting up the operating conditions of that unit for reverse, low and high.

Figure 27 shows in vertical section a modification wherein the manual unit of Figure 4 is replaced by a different type of gear arrangement.

Figure 28 demonstrates a modification of the control lever arrangement of Figure 15 in which an enforced shift made operative by the control handlever, is made available.

Figure 29 is a sectional view of the governor mechanism of Figure 5.

Figure 30 shows the form of the clutch plates of Figure 4.

Figure 31 describes the vertical section of the porting of valve assembly on the casing taken from the right of Figure 11.

' Figure 32 shows the arrangement of thrust sustaining means between the rotating members, and between them and the casing of the transmission.

Figure 33 is an elevation view of the transmission and main clutch casings on a'much reduced scale, showing the connection of the input shaft of the transmission with the engine, and the arrangement of the main clutch and accelerator pedals in dotted lines Figure 341s a control diagram of the relationships between engine speed, car speed as influenced by accelerator pedal, governor, and auxiliary controls which may supercede the automatic shift action at described points.

Figure 35 is a schematic diagram of the controls for the complete system, composing the supply aushowings of Figures 1, 4, 5, 8, 11, 12, 14, 15, and 27.

The reversing gear unit In Fig. 4, the vertical longitudinal section of the transmission structure shows the general relationships of the gearing and driving elements, with the forward-neutral-reverse gear unit at the right.

The clutch bell housing of Figure 33 is attached to the transmission casing 2 by bolts (not shown). Web 4 separates the forward-reverse unit from the rest of the transmission, except for the sump oil connecting passages.

Clutch driven shaft 5 is mounted in the easing by ball bearing 5, and input gear I is fixed non-rotatably thereto. The helically splined shaft ,8 of the forward-reverse unit pilots the forward end of shaft 2|, where thrust bearings l and Ill deliver certain axial thrusts originating in the system of gearing and shafting to the easing through bearing 6. Thrust bearing I9 is in the pilot space between shafts and 8.

Driven shaft 8 carries drum II, the inner surface of which is internally toothed at I! to form the input ring gear of the automatic unit. Bearing |3 in web 4 supports shaft 8 in the casing 2.

Countershaft |5 is supported at either end in bearings l4 in the casing. The first gear element l6 of the countershaft constantly meshes with input gear 1, and is fixed to countershaft I5.

The second gear element ll of the countershaft may be meshed with slidable reverse idler l8 supported in casing 2. The reverse idler gear I 8 may also be meshed with sliding gear l9 splined to and slidable on splines 9 of shaft 8. Teeth l9 are meshable with teeth 1' of gear 1.

The transmission lubrication and servo pump rotor 2|], of the pump assembly to be described later, is driven by countershaft l5. The construction is shown in Fig. 4. The pump operates constantly, whenever rotational power is applied to clutch driven shaft 5.

The automatic unit Shaft 2| in splined to carrier 22 of the automatic unit, and is piloted at the front end in shaft 8, and at the rear in shaft 59. Ported oil passages deliver servo and lubrication oil pressure to various units as will be described later. Shaft 2| is the power output member for the automatic unit. 1

Fixed to carrier 22 are spindle shafts 23 for planet pinions 24, which are three in number. Pinions 24 constantly mesh with the inner toothed ring l2 of drum H, and with sun gear 25. The latter is integral with sleeve 23 rotating on bearings 21 on shaft 2|; the sleeve 26 being bolted to webbed brake drum 28. Drum 28 has webs 29, and 30. Bolts 32 support clutch plates 33. Pinions 24 rotate on bearings 23' on shafts 23.

Extension drum 34 riveted to carrier 22 by rivets 3| is externally splined at 35 for clutch plates 35 which are engageable with plates 33, detail of which is shown in Figure 30. Governor drive parts are shown in Figure 5, in relation to the gearing of Figure 4.-

The manual unit In the manual unit, shaft 2| has aifixed to it sun gears 31 and 38. Drum 39 rotates on bearings 40 and 4|, and with toothed annulus 42. Pinions 43 and 44 mesh with sun gears 31 and 33 respectively, and pinion 44 meshes with annulus 42. Carrier 45 for pinions 43 is integral 'with or fixed to the final output shaft 50, having affixed pins 46 which serve as shafts for pinions 43.

The connecting elements between the two planetary groups are; annulus gear 5| meshing with planets 43, overhanging drum 52 and planet pins 53 on which planets 44 rotate. It will be seen that the parts 5|, 52, 53, and ring 54 constitute an intermediate floating assembly or element which never is connected directly so as to transmit torque, or never held from rotation so as to furnish torque reaction.

Bearing 49 forms the rear support of the manual unit in the web 48 of casing 2. Thrust bearing 41, identical in construction with thrust bearing l0 transmits axial thrusts between shafts 2| and 50.

Drum 39 serves as the mounting of clutch plates 55, through web 55, section 51 and bolts 58. The mating interleaved clutch plates 60 are mounted in the splines of clutch drum 59 splined to shaft 2|.

Shift actuation. means The ratio shifting controls integral with the transmission assembly are as follows. In the forward-reverse unit, slider gear l9 may occupy three positions; forward drive when clutched to teeth I of gearbody 1; neutral; and reverse drive when meshed with reverse idler gear I8. Yoke 190 is pinned to slider I04 mounted on rod NH and controlled through arm I92 and shaft I03. This linkage is shown in Figures 1 and 5.

In Figure 8 is shown anchored at 9| in casing 2 one end of brake element 99. Pin 92, locked by a nut, engages the socket of anchor piece 9|. The free end 93 of brake 90 at socket 901) engages piston rod 290. This brake element as shown consists of multiple turns wrapped so that upon fluid actuation when the unit is operat ing, the self-energising force does not act until the drum has reversed through zero speed. Preset or pre-energised springs, held oif by the fluid pressure system to be described, are effective to actuate the brake for self-energisation. The actuating forces of clutch release are provided by springs 88. The detail of the servo system is shown in Figures 11 and 35. The brake 89 of the automatic unit is identically constructed, and anchored at 82, Figure 15.

Clutch 556|l couples reaction drum 39 to shaft 2| to establish direct drive in the manual unit, and brake 90 prevents rotation of drum 39 and annulus gear 42 to establish reduction reduction drive by alternate operation of the brake or clutch respectively, yielding four net forward speeds, as in the following examples:

Ratio Automatic unit Manual unit 1 3. 375/1 Reduction Reduction. 2 2.25/1 Direct Do. 3 1. 5/1 Reduction Direct. 4 ill Direct Do.

For example, with reduction ratios of 1.5 to 1 Now if we shift themanualunit to direct, and

the automatic unit to reduction, we obtain a net overall reduction of 1.5 to 1. Direct drive in both units yields 1 to 1, all elements rotating together. It is entirely feasible to obtain all of these ratios superimposed on the reverse drive gear ratio, but is unnecessary for passenger car purposes. The output shaft may be connected directly to the final drive of the vehicle pru- 'peller shaft through the customary universal joint, or it may be joined to a distributing system of shafting involving multiple connections to the vehicle wheels.

Thrust compensation of the gearing is not compensated 'for are uniformly distributed to the casing, the

proper placing of thrust resisting elements being an essential feature described in conjunction with Figure 32.

In the automatic unit the axial thrust on the input annulus I2, under engine torque, is toward the engine or to the right in Figure 32.

Corresponding thrust in the pinions 24 is opposite. Between sun gear 25 and pinion 24 the residual thrust is exerted to the left and is taken through washer 94 to shaft 2|, bearing 41 and shaft 50.

The shaft 50 is supported in web 48 of easing 2 in bearing 49, and extends into said casing. The

shaft will hereinafter be known as the output shaft of the manual unit.

The adjacent end of shaft 2| rests against disc a and balls b of thrust bearing 41 which transmits compressional forces between the shafts resulting from operation of the gearing.

As noted above, integral with shaft 2| are helical pinions 31 and 38, shown in the drawing as of the same diameter; but not necessarily so according to my invention. The teeth of pinions 31 and 38 are cut with right hand helices, and mesh with planets 43 and 44 respectively.

Shaft 50 is integral with carrier 45, the latter supporting planets 43-mounted on pins 46 and bearings 6 I. Shaft 50, the output element of the gearing, may be connected to the driving wheels of the vehicle, or to the propelling means such as an aircraft propeller hub in any desirable fashion.

overhanging annulus gear 5I meshes internally with planets 43 and its web or extension 52 carries planet spindles 53 and bearings 52, which support planets 44. Ring 54 is joined to web 52 by through bolts 53, and is supported against axial movement by thrust washers 64 and 65. The bearings SI and 52 are of the multiple needle type.

Drum 39 rotates freely on bearings 40 on hollow shaft 50, and on bearings 4| on drum 59. The drum 39 is ground externally to form a braking surface, and rotating independently therefrom are the internal gear teeth 5| meshing with planets 43. Planets 43 and 44 are cut to left hand helices, and likewise the overhanging gear 5I and annulus 42. Integral with drum 39 is the driven clutch assembly 55 to be described later. The

driving clutch assembly 60 mounted on drum 59 rotates with shaft 2| as hereinbefore noted. Be-

tween carrier 45 and the overhanging web 51 of drum 39 is thrust washer 66. Shoulder 61 of shaft 50 and shoulder washer 10 abut bearing casing 2.

Recessed in cylinders 1| in flange 29 of drum 28 58 of web 51, through 49 inset in web 48 of are clutch pistons 12, guided by pins 13 in presser plate 14. Similarly, cylinders 15 in web 58 of drum 39 are fitted with pistons 16 guided by pins 11 in presser plate 18. Drilled passages 19 lead to cylinders 1| and passages 19' lead to cylinders 5.

Lubrication and servo system The main supply of transmission lubricating oil for all three transmission units is kept in the sump 2I9. The main drive for the pump is by means of shaft I5 to which rotor gear 20 is fixed. The pump is operating at all times whenever shaft 5 is running by virtue of the drive transmitted through gears 1 and I 8. The construction is shown in Figures 4 and 6.

The suction space to the pump leads to port I10 attached to outlet port "I of the oil cooler unit which consists of cartridge I13 dimensioned to fit recess I14 in casing I12 bolted to web 4 of the transmission housing. The cartridge is flanged at I15 to fit external seat I16 of the recess I14, and readily removable by bolts I 11. The water header I18 is enclosed by shell I19, divided by baiile I83. The upper half I of the header I18 leads through fitting I82 to pipe I84 connected with the pressure pump I81 of the engine cooling circulation system. The lower half I85 of the header I18 is fed through fitting I86, and pipe I88 connected at another point with the engine cooling circulation system. The water header I89 is drilled out to accommodate flanged or turned pipes I90 nested so as to provide uniform clearance, the opposite ends of said pipes being similarly fitted into the water header I18.

The cooling water flow is therefore through one half of the tubes I 90 from inlet pipe I84 of the water header to the header I89 shown in Figure 7, and then through the remaining half of the tubes I90 to the outlet pipe I88 of the water header. Heat exchange takes place through the walls of the pipes I90 to the water from oil which is drawn through long slot I9 I over the tubing I90 directed by batlle I92 to the outlet port "I, of smaller aperture than slot I9I, so that relatively low velocity of oil ishad at the point of oil pick-up from the sump. This is a novel combination of oil cooler with servo and lubrication pump having special advantages for bringing the point of heat exchange adjacent the spot where heating of the oil beginsnamely, at the pump rotor 20, and the mounting of the casing I12 which is a backing web for the pump as well as a support for the oil cooler unit, is of unique benefit in mounting economy as well as in handy assembly. Driven pump gear 20' is spindled to rotate in a portion of web I93 integral with web 4.

Pump suction is exerted at space I10 because of the we1l-known effect of gear pumps, and pressure is developed as long as.rotor receives drive through the described gearing path. Driving in reverse does not affect the positive delivery of the housing, which bears against the upper end and lifted by pressure furnished by the pump through milled leads I05 and I01.

The valve member 200 is a ground fit in this passage I99 to form seats between the ports which will now be enumerated; port 202 at the lower position, open to lead I95 from the pump; port 203 connected to the transmission lubrication main 220; port 204 connectable to lead I91 to the pump; port 206 connected to exhaust hole 2"; and port 205 connected to the servo pressure main 238. Flange 201 acts as a stop and affords a seat for spring 20l. A smaller extension of 200 fits bore 209.

Valve member 200 has a connecting drilled lead 200 which may deliver pump pressure from bore 208 to the transmission lubrication main 220 through port 203. A flat 2 cut as shown also provides immediate circulation of lubricant, even when the engine is idling, as shown in Figure 19. Assuming an increase of pressure in the pump, valve member 200 will rise as pressure builds up behind abutment M0, to the position of Figure 20.

This is accelerated by the exposure of pressure to a greater area as the lower area of 2l0 passes the lower limit of port 202. Now when abutment 2 of valve member 200 exposes port 204, the fluid pressure from lead I91 may now be delivered through port 205 to the servo pressure line 230 as shown in Figure 21. Now pressure from lead I96 is supporting the valve member 200 in the new position.

This is the normal running position of the valve 200. A decrease in pump pressure below a minimum causes valve 200 to move down until drilled lead 2l3 discharges into port 203 and dumps the oil from the servo line into the lubrication main 220 through space 2l2. Projection 2i0 may enter readily bore 209 since the oil cushion at that point is relieved through passage 208 and fiat 2. Initial pressure lifts abutment 210 when the pump is started up.

When operating at extreme speeds, the pump would create more pressure than the system requires unless means to relieve the excess were provided. At such pressures, valve is in the extreme up" position with spring 20l fully compressed as in Figure 22. At this setting, abutment 2!! is opposite the upper limit of relief port 206.

Excess pressure from pressure lead I01 may escape direct to port 206, whence it goes back to the transmission sump by relief hole 2| 1. This does not blow off the servo, since port 205 is connected by restricted passage 2l3 to relief port 206, so that when running at high speed, and the relief action occurs whenever the pressure requirement is exceeded, no disconcerting change in the operators control over the servo mechanism occurs.

The utility of this valve and porting combination is that it maintains uniform servo line pressure, yields a positive servo cut-01f at a given minimum pump pressure, and protects both servo and lubrication systems against excess oil pressure. An additional feature is the utility of the leak pass 21 4 at idling speeds for initial lubrication.

The unique feature in this construction is the rapid release of servo pressure, which prevents hunting and consequent slipping of the clutches and brakes in the transmission assembly; a feature of unusual commercial value, in that exccssive wear and heat are avoided.

This device can be preset to operate at given pressures by adjustment of screw fitting 2|. in

of spring 201.

Conduit 220 connects to passage MI in web 4 of housing 2. Oil may flow freely from 22I to annular channel 222 out in the external portion of hollow shaft 8 of gear l2. Drilled holes 223 connecting to channel 222 feed oil to the passages 224 transverse of shaft 2|. Longitudinal passage 225 in shaft 2| carries lubricant to the gears of both the automatic and manual units. The thrust bearing l located between shafts 8 and 2| is oiled through hole 225.

Side-cut passage 221 in shaft 2| delivers oil from passage 225 to a series of drilled outlets 228 in the sleeve of 22 and a series of drilled outlets 228' through the shank 26 of reaction sun gear 25. 011 may flow axially through splines 229 to the space between the web of carrier 22 and the adjacent face of drum II to teeth l2 and planets 24. 011 also passes through bearings 21 to the teeth of sun gear 25, by washer 230.

Drain out of such oil under pressure finds its way back to the sump 2|9,,the opening of clutch 3338 relieving the accumulated oil in the drum.

Side-cut outlet 232 connects passage 225 so as to lubricate thrust washers 84 and 65 and the meshing teeth of gears 38 and 44. Similarly, drilled outlet 235 delivers oil to the teeth of meshing gears 31 and 43. A third outlet 236 feeds oil to bearing 231 and it passes from that point to drilled hole 230 in shaft 50 to bearing 40 between the sleeve of drum 51 and the shaft 50. Bearing 49 in web 43 receives oil from this pressure source.

The forward-reverse unit obtains oil under pressure from main passage 225, passage 226 in l0a'-l0c', and passage 225' in shaft 8. Outward flow in thrust bearing l0 may deliver oil to the pilot bearing 59. Further lubrication of the unit is by customary dip in the sump level oil. Because of the rigid compartment construction of easing 2 it is possible to seal the entire assembly with oil pan 23l, which acts as an oil reservoir, sealing means 2| 6 providing a tight joint at all contact points.

The use of a common sump for all three gear units yields advantages for uniformity in cooling, rapid re-circulation, and maintenance of proper capacity requirements, as well as providing a oneflll job for service replacement of oil. It is worthy of note that the resistance drop of the circuit of oil pressure mains is so arranged that with very slow engine speeds, as at idling, a plentiful supply of fresh oil is pumped through the transmission units. This is available the instant the engine starts up since the countershaft which drives the oil pump gear 20 is constantly driven from ghelnain clutch driven shaft through gears For servicing and test the main clutch pedal 300 of Figure 33 may be used as a master control over pump drive. In the prior art, dump valves to relieve servo pressures, or equivalent shortcircuit or cut-off devices appear, connected to separate items which perform the cut-off function. In some cases these are shown attached to accelerator linkage to shift levers, and to separate control elements mounted on dash, steering column or instrument board.

To relieve the driver or servicer from learning new modes of operation, I arrange .the servo mechanism so that when the car is standing still, the driver may warm up a cold engine by holding the main clutch pedal 300 in disengaging position. This operation may be carried on without forcing oil unnecessarily through the servo system.

When the car is in motion with jaw clutches 1'I3' engaged, the pump gear is always supplying servo and lubrication pressure. If the Jaw clutches are disengaged by shift of the hand lever 30I to neutral, the pump still will be driven by the engine, until the main clutch is disengaged by pedal 300.

To withhold drive from the pump, it is therefore necessary to shift the hand lever 30I to neutral, and hold the main clutch open which establishes a safeguard against the pump being inoperative at any time, unless the car driver so wills it.

Ratio control linkage Rod H0 is moved by the governor toward the left in Figure 15 as engine speed increases. It is pivoted to equalizer bar I II at slot H2.

The opposite end of the equalizer bar III is pivoted to rod H3 at I30, and near its center,

slot H4 is engaged by pin II 5 set in scimitarshaped lever H0. The latter lever is pivoted on shaft I20 as a center; carries spring stop H1 and also pins H0 and H5.

Opposing spring stop H3 is integral with lever I2I fixed to hollow sleeve I22 surrounding shaft I20, the outer end of which carries lever I23 having cam-end I24 (see Figure 14). Intermediate spring I25 transmits forces in compression between levers I2I and H0, the spring stops H3 and H1 preventing the spring from leaving position.

, Pin H0 in lever IIO may engage long cam slot I21 of plate I 20 rotatable on shaft I52, the function of the slot being to prevent or limit clockwise rotation of lever IIO, except when in high speed position.

Adjustable stop plate I20 is also pivoted on shaft I20 and adjusting clamp screw 30 is used to fix the angular position of plate I 20,. by reference to slot I30. The fixed stop I3I and the adjustable stop screw I23; establish the range limits of movement of the cam end I24 of lever I23 about center I20. Stops 315, 310 limit motions of H0 and I2I.

Lever I32 is mounted in the external lever compartment of Figure 14, rotatable freely on shaft I20 and its stop or lug I33 turned away from the observer's eye may engage the lower edge of lever I23. Lever I 32 is linked to rod 30I at clevis I34, and responds to the accelerator pedal movement of Figure 1 where the forward end connections of rod 30I are shown. Fig. 17 shows the connections about shaft I20 between the externally and internally mounted levers of Figures 14 and,15.

For a given position of governor link pivot II2, lever I32 may rotate about center I20 clockwise, stop I33 will engage lever I23, whose arm I2I and spring stop II9 will then compress spring I25 applying an increasing force to cause clockwise motion of scimitar-shaped lever IIO. Pin

I I5 thereupon exerts a leftward force upon equalizer bar I II, and on link lever II3 attached to it at pivot I30. r

An increase in governor speed will tend to shift pivot I30 to the right, tending to counter,-

act the above mentioned force.

On fixed pivot I31 toggle arms I38 and I33 are mounted, the lower arm I38 being pivotally attached to coupling I40. The engaging end of link lever II3 coacts with coupling I40 assisted by spring I recessed between guide lug I43 and the pin I40 on link lever II3. Thus a rightwardly exerted force in rod II3 acts on coupling I 40 to cause arm I30 to swing counterclockwise about fixed pivot I31.

The upper arm I33 01' the toggle is yoked to valve body I00 by loose pivot I44, and also at the upper end, carries weighted pivot I45 in slot I40. Toggle spring I40 attached to arms I30 and I33 and I43 and I45 respectively, stores energy for snapping the valve right or left, as pivot I43 of arm I30 is moved past center with relationship to fixed pivot I31 and pivot I45 of arm I33.

When valve body I is in the right hand position as will be seen later, fluid pressure is admitted to hold 011 brake 00 and engage the clutch 33-30 of the automatic unit. When it is in the left hand position, the fiuid pressure of that system is released and the automatic unit is put in low gear drive by spring 01 actuating brake band 00.

' Plate I20 rotating with shaft I52 is rocked by movement of externally mounted lever I 5| attached to shaft I52. The latter lever is joined to rod 3I0 at clevis I53, and selection movement of hand lever 30l of Figure 1 acts to shift lever I5I to operator-selected positions, through 3I0, pivots 3| I and 303, rod 300, clevis pivot 301, arm 300, shaft 305 and lever 30I.

The interaction of cam slot I21 with pin 0 is useful in eliminating downshift of the automatic unit when the handlever 30I is in low, cam I21 restraining pin II8. Resumption of "high drive restores the coaction by moving cam end I21 out of contact with pin I I0, whereupon the latter is free and automatic action is resumed.

Irregular cam slot I cut in plate I20 actuates the valving connected withthe operation of the manual unit. Projection I50 acts as a stop engaging with toggle arm weight I45 to prevent automatic shift to high ratio in the automatic unit, after the plate I20 is in reverse position. This is known as the automatic unit lockout mechanism.

The lever I51 (see Figure 11) pivoted at I50 on the casing carries lug I00 which engages lever I00 counterclockwise. Lever I00 moves valve I 00 at 230 and carries pin 234 which may strike lug I01 of lever I01. Spring IOI bears against lug I00 and permits I51 to swing clockwise when pin 234 may be restrained. Pin I53 of lever I51 fits cam slot I55 of plate I20. The centers I52 and I50 are taken with respect to the arm I 50-I53 and the radii of slot distances from center I52 so that movement of arm I5I by rod 3I0 forces lever I51 to follow clockwise motion of lever I5I, actuating valve I00 of the manual unit, shown in Figures 12, 15 and 35.

Valve I03 is moved by lever I00 through head 230 and follows the movement of lever .I5I. When the lever I5I is in its limiting counterclockwise position as in Figure 15, the valve I 00 is at its bottom limitof travel, and when I5I is at its limiting position in the clockwise direction, with pin I53 in the reverse position of slot I55, the valve I03 is in its extreme up position. Further text describes the effects of these positions on the fluid servo system valving.

Connecting rod I35 attached at pivot II2 to governor rod H0 is pivoted to lever I01 at I35. The lever I01 is pivoted on valve case IOI at I00 and its upper end is turned over to form curved lug I01. Pin 234 on lever I00 moves in an arc to be intercepted by lug I01 at maximum governor speeds, so that the manual unit valve It! cannot be moved up, or raised from its position which establishes direct drive in the manual unit. Cover plate I94 is bolted to housing 2 and protects the lever assembly of Figure from dust and dirt. Pin I35, spring I54, and slot I35" in rod I35 permit governor action to proceed without being affected by jamming of I61 through forces on I60.

Servo controls Mounted on the left side of the transmission are the control linkages of Figures 11, 14 and 15, and whereby the selection of transmission speed ratio is accomplished.

In Figure 11 valve case I6I is bolted to the transmission housing at I62 and I63. At the left is socket I64, which receives the projected end of governor connected rod IIO for alignment purposes. At the right is toggle support I65 for pivot I31. A downward extension of the valve case casting terminates at the right in guide lugs I43, between which lever link H3 is constrained to move. Pivot pin I66 projects toward the eye of the observer and is a mounting for lockout link I 61 of Figure 11.

To provide a clear idea of the construction of the valve case I6I, Figure 12 shows a right angle section view taken vertically through the cylindrical portion of the case which embraces manual unit valve I68, and taken horizontally through a section of the case which forms a cylinder for the automatic unit control valve I50. At the left in this figure are shown five ports which will now be enumerated in order;

The uppermost port, 260, relieves fluid pressure from the cylindrical space 26I, dumping the from whence it drains back to the sump 2I9 of the transmission. The second port, 262, leads to the outlet of the casing, from where the oil may flow to the control cylinder 292 for the manual unit. The port 263 below is the inlet from the servo pump, and it receives oil from passage 213 through the porting shown in Figure 3|. The next port, 264, delivers fluid pressure to passage 211, from where it is used to reinforce the load spring 91 of Figure 8. Walls 283 and 293 seal cylinders 282, 292.

The lowermost port, 265, leads to passage 216 and furnishes fluid pressure for reinforcing the spring pressure on brake bands 80 and 90 of both the automatic and manual units.

When the valve I68 is in the uppermost position, the pressure from the servo is admitted to both ports 264 and 265 below it, as in Figure 23, this reinforcing the brake bands of both units as in Figure 35. This reinforcement also is applied to the subpiston 294 of Figure 8. When the valve is in intermediate position as shown in Figure the pressure is cut off from the lowermost port 265 and is only effective through port 264 to reinforce springs 91 by furnishing pressure back of subpiston 294. This is effective when the hand lever 30I is placed in the low position on the indicator plate 302. During downshift from direct to low speed ratio in the manual unit, this port relationship is effective, as well as "when in neutral."

When the valve I68 is at the bottom of its stroke or in the high position of Figure 26 fluid pressure from 263 is admitted to port 262, and is effective to overcome the force of spring 91 exerted on brake 90, as well as exert pressure upon clutch plates 55-60. Port 260 is effective to drain the manual unit cylinder 292 through port 262 and space 26I when the valve I 68 is moved back to the low-speed position.

To the right of preceding described portings, Figure 12, shows a horizontal section taken at 90 to the plane of the preceding section of the manual control valve porting. Port 266 at the extreme right of this section is connected with passage 238, which also feeds servo pressure to port 263 described above. Port 261 leads to passage 214, which delivers fluid pressure to the actuating members of the automatic unit as shown in Figure 11. Ports 266 and 269 are cut through to the external face of valve case I6I and may deliver relieved fluid pressure from the cylinder of the automatic unit and connecting passages as well as from the space back of valve plunger I50.

.Figures 12 and show valve plunger I for the control of the automatic unit in two different positions; first, in the position where fluid pressure is shown flowing from port 266 to port 261. As long as it remains in the right-hand position the automatic unit will remain in direct drive. In Figure 35 the valve plunger I50 is shown in the left-hand position, where fluid pressure from the cylinder of the automatic unit is allowed to leak out from port 261 through the space between the abutments of the valve and out the relief port 266 to drain back to the transmission sump. The automatic unit can not ever drive in direct when the valve is in this left-hand position.

The mechanical movement which requires the valve to occupy the described two positions is shown in Figure 15, where loose pin I44 connects the extension of valve I50 external to the case I6I to toggle levers I 39. action of the toggle mechanism has been described preceding. Bolts I62 and I63 are used to support valve casing I 6| on the face of the casing 2, which embodies the actuating mechanism for both the manual and automatic units. The casing is continuous with the transmission housing, and embodies certain ports which match with the ports described preceding in connection with the valve case I6I; namely, 262, 263, 266, 265,266, and 261. The face of valve case I6I embodies passage I69 leading from port 261 to port 215. Figure 31 shows the ports 213, 211, and 215, which respectively are for servo inlet, reinforcement, and automatic direct drive; Port 212 connects manual unit cylinder 292 with port 262.

Port 213 in the casing is the servo pressure delivery source feeding to channel 210 out in the inner face of valve case I6I leading to both ports 263 and 266.

Passage 215 is the inlet pressure line which delivers oil from passage I69 to overcome the spring load against piston 28I, which moves in the cylinder 282 of the automatic unit.

Slotted in the casing is passage 216 leading to the space behind the pistons of both the automatic and manual units. This port registers with port 265 of valve case I6I. (See Fig. 13.)

Likewise drilled in the casing is diagonal passage 211, which registers with valve case outlet port 264. This passage leads to the space behind subpiston 294 as is described in connection with Figures 8 and 35.

Valve I68 is moved vertically through lever I51 pivoted at I58, and is free to follow the movement imposed by pin I59 in following cam slot I of cam plate I26 as lever I 5| is rocked about the axis of shaft I52. The only interval in which this free movement of valve I68 may be interrupted is through the intersection of lever I61 and its The two-positional curved stop I81, which may at high governor speeds prevent the shifting of valve I88 to lowspeed position from direct drive position through the agency of pin 234 fixed to lever I88. This definitely locks the valve-shift movement until the governor speed has fallen sufliciently far to release stop I81 from pin 234, whereupon the vehicle driver may resume hand control. The purpose of this arrangement is to prevent abuse of the driving mechanism.

Clutch feed lines 218 and 219 are shown in the section view of Figure 9. An extension web 289 of the casing 2 encloses the shaft 2I, and lines 218 and 218 terminate in drilled passages 281 and 288 in web 289, which lead to passages 19 and 19' of both units. Flanges 388 and 38I of web 289, with packing 382 form glands to reduce loss of oil pressure.

The passage of clutch fluid pressure from cylinder 282 of the automatic unit then flows through 218, 281, and 19 to cylinders H in drum 28. Likewise the flow from cylinder 2192 of the manual unit passes through 219, 288, and 19' to cylinders 15 of drum 39.

Servo actuating mechanism Figure 8 is a transverse vertical section through the transmission assembly. Drum 38 of the brake band 98 to grip drum'38 being supported by base plate 293. Subpiston 284 slides in secondary recess 285 when fluid pressure is applied for down shift, low speed drive, or reverse as described preceding. The three conditions of operation of this structure are; first, fluid pressure may be introduced above the head of piston 29I to counteract the force of springs 91 and 91' and thereby release brake band 88 from drum 39; second, fluid pressure admitted to subpiston cylinder'295 may augment the gripping force of band 98 finished by springs 91 and 91; and third, fluid pressure may work simultaneously behind both pistons 29I and 294 reinforcing these springs when the car driver desires to proceed in reverse gear.

The necessity for the latter over-all reinforcement is to overcome any self-actuating rejection forces caused by the retrograde rotation of drum 39, as will beapparent from study of the directional torques involved in reverse drive.

The construction of the brake bands 88 and 98 themselves is of interest, in that as used in this transmission they are especially contoured and designed to accommodate the directional torque requirements. Figure 8, where fitting 288 is attached to the ends of spiral band 88a by countersunk rivets. Socket 98b is cut to receive the end of the rod 298. The direction of wrap 'of the band of the automatic unit, in this case band 88, isin a lefthand spiral, and the direction of wrap of band 98 of the manual unit is in a right-hand spiral. This construction enables one to combine the actuating mechanism in a centrally located control housing for the operating mechanism, both being organizedon an interlocking basis. End 88b corresponds to 98b.

This construction is shown in- It will be noted that, for example, when both units are in direct drive and the mechanism is caused to establish low speed drive in the front or automatic unit, that a certain degree of rejection force of the movable end of 83 of the band 88 takes place when spring 81 is permitted to exert itsforce in a direction to endeavor to lock the bank to the drum 28. This takes place continuously until the drum is brought to zero speed, after which retrograde movement brings into effect self-wrapping action more or less proportional to the coefllcient of friction and to the forces involved. The net result of this action is to friction-synchronize the drum for zero speed, thereby establishing reduction drive through the gearing at the instant the drum ceases to rotate. Equivalent action takes place under similar circumstances when the direct drive clutch 55-88 of the manual unit is released and the brake 'band 98 energised by springs 91 for locking the drum 39. We therefore have in both units selfsynchronizing means, both of which may be made active by shift of hand lever 38l to low position under certain operation conditions.

Manual shift controls The bracket 384 is shown attached to the steering column in Figure 2, forming a bearing for shaft 385 and a mount for sector latch plate 3I5 and indicator plate 382. Handlever 38I attached to shaft 385 swings in an arc, its latch button 3I6 and latch rod 3 moving longitudinally within one end of the lever. The notches 3I3, 3I4, 3I8 and 3I9 correspond to high, low, neutral and reverse respectively. Spring 323 tends to seat roller 324 attached to rod 3I1 against the notches'as in my previous application U. S. S. N. 747,386 filed October 8, 1934. In Figure 3, an extra notch 3I3' is shown for the enforced 3rd shift described later in these specifications, and 382' is the modified indicator plate.

Reciprocating motion of the lever results in corresponding reciprocation of the shifter rod 388, pivots 389, 3 of lever I89, rod 3I8, and pivot I53 of lever I5I, as seen in Figures 1 and 35.

To clarify the description, Figures 28 and show the cam plate I 28 marked with captions. In Figure 35, the relative positions of pin I59 in slot I are given as Rev.," Neut., Low, and High. In Figure 28, the extra mark 3rd" on plate I25 indicates the enforced third speed shift position. In practice these gauge marks may be used to assist service adjustment.

Governor drive 'to hub 244 at 249 and terminate in cam ends 258 and weight ends 25I.

External large coil spring 252 rests against plate 241 and fits recessed seat 253 in the flange of hub 244. Internal coil spring 254 likewise rests against retainer plate 241 and presses traveler sleeve 255 to the right in Figure 29.

This sleeve 255 is hollowed out to a bearing fit over the spindle end 258 of shaft 24I and may slide freely axially, as thrust by the end of spring 254 acting on flange 259.

at the external end of sleeve 255 collar 251 operator to vary the effect of the throttle motion as indicated in Figure 15. Normally at rest,

the assembly of governor parts is as shown in Figure 29. As applied speed increases, weights 25I of arms 246 swing about pivots 243 and cam ends 250 shift sleeve 255 against the tension of spring 254. When the sleeve has moved a predetermined distance, the score seat 233 of the flange 253 of sleeve 255 abuts end of spring 252, and further increase of applied speed results in weights-working against the combined stresses of springs 254 and 252. It will be seen that the relative travel of sleeve 255 for a given speed increment in the latter phase is less than in the prior stage. Variations of governor speed above a predetermined point can create no change in the external control mechanism.

In Figure 35 the collar 251 is arranged to move arm 350 fixed to shaft 35I, which latter moves arm 352 pivoted to governor rod H at 353. In

this way axial motion of sleeve 255 is converted to reciprocating motion of governor rod IIO, pivot I I2 and rocking of equalizer bar II is accomplished.

Accelerator pedal linkage The relationship of the accelerator pedal and handlever linkage are shown in Figures 1, 15 and 35.

Accelerator pedal 303 is pivoted at 354 on the floorboard of the driver's compartment, and rod 355 is pivoted at 360 so asto be moved freely by the pedal 303. Return spring 351 serves to restore the pedal to minimum throttle position. Connection 363 isto the engine throttle. I

Bracket 358 provides a pivot for lever 353, the rod 355 hooking into hole 360, and rod 36l being attached to lever 353' at pivot 362. Depression of the accelerator pedal 303 willtherefore exert a thrust on rod 355, lever 353 will swing clockwise, and consequently rod 36I will be pulled toward the left in Figure 35. This action rocks lever I32 through clevis pivot I34 and shaft center I20, causing stop I33 to engage-lever I23. and move upon the shift control.

I Forced shift controls An important modification of the control linkage of Figures 15 and 35 is shown in Figure 28. The modification is for the purpose of permitting the vehicle operator to compel drive indefinitely at the driving ratio next below high, in the present exempliflcation, in fthird.

. lever, I2I attached to hollow shaft I22 clockwise.

Whenever spring I25 is so stressed, the impulse of -..i;he driver's foot is exerted to 'svving\lever-- I.I6 clockwise, consequently tending to move pin H5;

and bar'I II to the left. is the direction of movement to pull rod H3 of Figure'l5 to the left,"

which'may through the toggle mechanism I33 I33, snap the valve I 50 of the automatic unit into the low position. Wheneverjthe accelerator pedal 30I is,depressed, the "described :mecha'nism' then establishes a tendency J for valve I50 to- "dow'nshift." 1 a The-engine carburetor is shown at 364 in Figure 1, where throttle rod 361 is joined to throttle arm 365 at 366, the other end of throttle rod 361 being pivoted to lever 353. I H v i The adjustment at clevis I34 permits the service operator to set the operative relationship between required motion of the pedal 30I fora given effect on the mechanism controlledby rod 36 I and that at 366 may be set to determinethe movement of To accomplish this purpose, I modify lever I26, adding extension 320 to it, and mounting thereon the pin 32I arranged to move in a given are.

Lever I2I' moving integrally with lever I23 about the center of shaft I20, is notched at 322, the arc of movement of this surface being arranged to intersect the movement of pin 32I at a given point.

The cam plate track I55 is lengthened clockwise from that of Figure 15, so that pin I53n20 transferring the movement to lever I5l.

' The relative position of the cam plate I26 changes from that of Figure 15 to'that of Figure 28, and valve pin I53 slides around in slot I55 to "3rd" position. Simultaneously, pin 32I of arm 320 moves counterclockwise intersecting notch 322 of lever I2I', and rocking the lever assembly I2I-I23 clockwise until head I24 abuts stop I23 fixed to the casing.

This action is a duplicate of that occurring when the accelerator pedal is pressed to maximum, open-throttle position. Spring I25 is fully stressed, and transmits a leftward exerted force. to lever II6 through stop I". Pin II5 thereupon tends to pull equalizer lever I II to the left, and since cam toe I54 of plate I26 no longer can interfere with-the movement of lever II6 through pin .8, the'momentarypositioning of H2 by existing governor speed, establishes 2 as a fulcrum for equalizer bar II I, and pivot point I36 moves'leftwshifting rod H3 and pivot I40 on togglei.arin"l36 left. Thisbreaks the action of the toggle linkage since the shifting of pivot I40 movesthe'vend I43 of spring I48 past center, and toggle arm 'I 33 is forced to move to the left, thereupon shifting the control valve I50 of the automatic unit to the left. As elsewhere described,

releases the pressure in cylinder 282 and spring 01 of the automatic unit applies brake 80, establishing reduction gear drive in that unit,

since fl'uid pressure is therewith relieved from loading of-clutch' 33-36.

The automatic fgovernor versusthrottle shifting action herewith ceases, since the throttle pedal, position cannot further influence ratio shift because lever I23 is held flush with stop I23. The

governor connected linkage. has not, 'however,

been put out of action, but is still able to prevent abuse of engine'and transmission, in tfiat at an extreme high speecl .governor position, corresand acceleration available to the car driver with-v in definite speed ranges of engine and vehicle,

wherein neither engine nor transmission mecha- It will be noted that after an excess peed up- A shift to high compelled by the governor, when the setting is for enforced 3rd drive; the con- .rol mechanism will reset to "3rd when the governor speed falls, and drive in "3rd will be resumed, requiring no especial attention from the car driver. Resumption of normal automatic shift in the automatic unit is accomplished by resetting the handlever 30I in its high position.

This rotates plate I26 back to the position of Figure 15, and removes pin 32I from intersection with notch 322 of lever I2I'.

The motion of the handlever 30I from position 3 to 3| 3 and 3I3 requires a lost motion provision in the linkage of lever 308 of Figure 35 to shaft I03, lever I02, and slider I04, so that after jaw clutches 'I'I9 are meshed, the motion of 30I may be continued. Roller 3| 2 after completing the stroke of slider I04 toward mesh of 'I'-I9', may ride free of cam face I05 of the slider, so that the lost motion provision is herein accounted for. This is an important feature in that the cost of added lost motion mechanism in the rodding and leverage is dispensed with,-in the combination of the two motions of rocking of I02 and the sliding of I04 on rod IOI.

Modification-manual unit In Figures 4 and 8 is shown the construction of the double reduction true planetary gearing unit, but to extend the utility of my invention to types of transmissions fulfilling requirements for differing ranges of speed ratios, I deem the presently described modification showing advisable.

This consists in a. transmission unit of the type of the manual unit of my hereinbefore mentioned U. S. S. N. 747,386 filed October 8, 1934, so disposed in the general assembly of the present case, that it conforms to the mechanical and control requirements herein established. The object of this modification is to demonstrate the flexibility of application of my invention, and more particularly, the means by which I retain the advantages of my invention in a different arrangement of gearing, reaction sustaining means and actuating mechanism.

Figure 27 shows the continuation of shaft 2I delivering engine torque or a multiple thereof from the automatic unit to pinion or sun gear 325, meshing with gears 321 of compound planets 326 mounted in the webs 33011-4301) of carrier drum 330. Sun gear 329, aflixed to the final output shaft 50', meshes with gears 328 of compound planets 326.

The webs 330a and 330i) support the shafts 332 on which planets 326 are bearing mounted at 33I and the composite drum 330 is in turn supported on bearing 49 in the web 48 of casing 2, and on bearing 4| on the shaft 2|. Prime number items are identical with originals of Figure 4.

The thrust bearing 41 of Figure 4 delivers axial loads between piloted shaft 2| and recessed shaft 50, as in the preceding description of the double reduction unit. Planet pinions or sun gears 325 and 329 are helically cut to a right hand helical angle, and gear teeth 32'! and 328 of the compound planets 326 are cut to a left hand helical angle, the thrust pattern being similar to that of Figure 30, and to that of the preceding noted case. This arrangement yields a proper distribution of thrust loads, and a quiet, low-105$ gearing arrangement of unusual utility.

Drum 333 embodies fluid pressure cylinders 334 integral with web 3300, and fluid passage 335, as in the construction of the double-reduction unit of Figure 4. Clutch plates 33'! splined on hub 336 keyed to shaft 2I furnish the direct drive torque, and mating clutch plates 338 keyed on bolts 339 constitute the receiving members for the couple, presser plate 340 transferring the thrust of pistons 34I mounted in cylinders 334 to the plates, when direct drive is desired. Clutch release springs are shown at 345.

Brake band 342 identical with band of the previously described double-reduction unit, is anchored to the casing, and its movable end corresponds with end 9011 of band 90 of Figure 8.

The actuating means for this unit correspond in every way with the showing of Figures 8 and 11 and duplication of their function at this point is not believed necessary. Operation is therefore similar, but the ratio ranges available from the use of this form of gearing are in a different class from those of the double reductionunit. Furthermore, this unit is not a true planetary, since when brake 342 is locked to drum 333 there is no planetating action of the gearing but a strictly countergear action. This unit then is a rotatable reactor type, as distinct from one in which definite planetary rotation occurs under torque. The only time the present unit planetates is when the transfer from one driving condition to another takes place, i. e during the change speed interval.

Clarification of these points among those skilled in the art is desirable in that many actuationcontrol mechanisms useful in one type are definitely non-applicable in the other. My disclosures herewith describe the applicability of my invention to both types, which gives to the public a choice of use over a wider range of work requirements.

Overall thrust diagram Figure 32 is a schematic sectional elevation of the elements involved in the distribution of torque thrust resulting from the use of helical cut gearing. As explained preceding, in the automatic unit, the sleeve 25 receives a thrust to the left from sun pinion 25, delivered to shaft 2| through thrust washer 94. Shaft 8 receives a thrust to the right because of the inclination of the teeth at I2--24. Simultaneously, interaction between helical splines 9 of shaft 8 and gearbody I9 provides a thrust to the left, tending to counterbalance the preceding noted thrust, therefore a residue only is taken at bearing 8 through thrust bearing I0 and shaft 5. Parts of bearing 41 are shown at a, b, and c.

In'the manual unit, sun gears 3'I-.38 endeavor to move to the left, adding to the thrust on thrust bearing 41. Thrusts on reaction annulus gears 52 and 42 are to the right, but thrust washer 66 transmits a part of this effort to carrier 45, thrust bearing 41 acting to compensate; and thrust washer 65 delivering thrusts from annulus 5I to shaft 2I through thrust washer 65, ring 54 and clutch hub 59, also establishing a degree of compensation. On the overrun, clamped wash-' er I0 transmits opposite thrusts to bearing 49 from drum 39, and thrust washer 64 limits leftward movement of 5I52-54.

In the forward-reverse unit, the teeth 'I' of input gear Iv are cut to a left hand helix, to mesh with the teeth I9 of slider gear-I9, to form the means to drive in direct. Gear I9 is helically splined to shaft 8, the splines being cut to a left hand helix, corresponding to the helical cut of the teeth of IQ and I. I

This arrangement causes a thrust to be exerted so as to press gear I and shaft to the right as in Figure 32, and shaft 8 receives an opposite thrust which is delivered through thrust bearing 41 to shaft 50 and through bearing 49 to web 48 at the rear of the transmission assembly.

The external teeth of gear I are cut to a right hand helix and mesh with countergear I8, cut to a left hand helix,. so that when the reverse train is driving the gear I is urged to the left, putting a thrust on thrust bearing I8. The countergear unit IG-ll is supported in its bearings for longitudinal movement. At the point of mesh between II and reverse idler I8, the latter receives a thrust to the right; between I8 and I8 the thrust on I8 is to the left, tending to counterbalance the thrust received because of the drive of II. The net thrust on I9 is to the right at the point of contact with I8, but because of the helical cut of the left hand spline teeth of shaft 8 on which I9 is mounted, this tendency is counterbalanced. Net thrust in this unit is therefore toward the engine, exerted on bearing I0 and on bearing 6 when driving in reverse.

Ormui'rxon I Starting the vehicle at a given speed. The main clutch pedal 808 need not be depressed, since the handlever 30I in the neutral position separates the spinning clutch disc'and driven gearing from the final drive. In this condition, the operator may remain for as many minutes as are necessary to warm-up the engine, the servo pump gear 28 circulating the transmission case oil through the described passages.

When it is desired to put the vehicle in motion, the clutch pedal 300, depressed by the foot, separates the mating clutch plates, the operator thereupon shifting the handlever 3M to correspond to neutral to "low shift of plate I 26 of Figure 35. At this point/attention is directed to a valuable adjunct for absorbing the inertia of the main clutch driven plate, and connected parts. In my construction, the arrangement of clutch driven shaft 5, gears I and I6, and servo pump 20,, and automatic pressure valve 200, provides a predetermined back pressure when drive is removed from this system by opening of the main clutch.

The effect of spring 20l in compelling valve 200 to occupy a position such that developed pump pressures work against the head of the transmis-- sion.lines,.andtliereupon continue to cause 'oil to flow through the transmission bearings, provides a useful means to pace the inertia absorption to the synchronization requirements, to

achieve the net result of a smooth transition from neutral to low, so that jaw clutch I will reduce to zero speed very quickly. Further protection of this shift system is afforded by the chamferv of the teeth of bothjaws I' and IS in a left hand direction. From the well-known overrunning effect of inclined-toothmeshing clutches, it will be seen that with the main clutch engaged, the gearbody I9 has zero rotation, and gearbody I has engine rotation, and the bringing of the two together under these conditions would tend to causethe teeth I9 to reject mesh with the teeth of I. This rejection action continues until gearbody I is'brought to zero speed by the braking reaction of the pump gear 20 and system which it feeds.

Then there are these fulfilled functions in the neutral-to-low shift:

1. Braking action of pump 20. 2. Mesh rejection of I'--l9'.

One acts to establish synchronism-tending forces which cease to act when the inertias are absorbed the other simultaneously prevents mesh until the first function has been completed.

Assuming that forward drive has been synchronized, let us examine the operating conditions in the remainder of the driving system. As soon as the driver relaxes the main clutch pedal, engine torque is delivered to shaft 8, and to the input annulus gear [2 of the automatic unit. The car load is assumed'to beacting on carrier element 22, connected to shaft 2| which is the output shaft of the automatic unit.

With load on carrier 22, the engine torque on gear I2, a force is applied to the sun gear tending to give it a retrograde rotation, as shown by the arrow in Figure 10.

Brake band 88 of the automatic unit being normally stressed for locking by the springs 81, is so wound and anchored that slight retrograde motion of drum 28 tends to cause the band to self-energise, assisting locking against further retrograde motion.

This then establishes a reaction, gear 25 cannot further rotate, and cage 22 moves in the same d'rection as .the engine connected gear, the planets 24' moving orbitally as well as rotationally, shaft 2| being driven at a ratio to engine speed, forwardly.

In the manual unit, brake band 90 is so anchored and wound as to be self-energising for retrograde rotation. Sun gears 31 and 38 transmit the rotation of shaft 2| to both planets 43 and 44. In the first part of this unit the sungear 38 drives the planets 44 reversely on spindle 53, and annulus 42 being held by brake band 98, receives a retrograde reaction. Reduced forward motion is imparted to spindles 53 which being integral with annulus 5| of the second part of the unit, cause annulus 5| to have equal reducedforward rotation. Now sungear 31 is si multaneously driving planets 43 to revolve reversely on spindles 48, and if it be considered for a moment that if annulus 5| be held from rotation by a non-existing brake, carrier 45 and shaft 50 would have a certain net reduced forward speed, the annulus 5| taking a retrograde reaction. I

Instead of the annulus 5| being held, it has a forward speed component derived from carrier 52v of the first part .of the unit, therefore the net rotation of carrier 45 is modified to a speed, compounded from 'the' motions imparted through sungearf3I and annulus'SI. For example, if the net reduction of the second part of this unit comprising sungear 31, planet, annulus 5| and carrier 45 be estimatedat 4 to 1; and the re-' duction increment applied through annulus 5| by 

